New dataset to improve comparative electoral research

A team of WZB researchers has compiled a comparative dataset of election surveys covering 128 national elections in 51 countries from 1994 to 2011. These election surveys had been collected by the Comparative Study of Electoral Systems (CSES). The new dataset, which was assembled by Bernhard Weßels, Heiko Giebler, Josephine Lichteblau, Antonia May, Reinhold Melcher (now Fern-Universität Hagen) and Aiko Wagner was made accessible via the CSES website on June 1st.

The CSES is a collaborative program of national election studies around the world devoting itself to comparative electoral research and investigating the behavioral impact of political institutions since 1994. It provides survey data on elections for a large set of countries, however, these had not been combined in a single comparative dataset up to that point.

The WZB team of the German Longitudinal Election Study (GLES), which is responsible for the German contributions to CSES, now published a Harmonized Trend File of CSES Modules 1 to 3. Members of the CSES are national election study teams that agreed to include a common module of survey questions in their representative post-election studies, each for the duration of about five years. This common module of questions is developed by the CSES Planning Committee, that first Hans-Dieter Klingemann and then Bernhard Weßels from the WZB were part of from 1995 to 2014.

The CSES 1-3 Harmonized Trend File is not simply a merged version of the three single datasets of the three modules containing each survey question/ variable of each module in their original form. For the Trend File all micro- and macro-level variables that were part of at least two of the three time waves have been cumulated and partly integrated across the modules and participating countries. Thereby, the variables have been merged into one harmonized variable containing all cases of all (or up to) three waves in the harmonized dataset. Coding of these variables has been harmonized as well to ensure that values represent the same substantive content over all waves and countries. Therefore, the CSES 1-3 Harmonized Trend File provides a sound data source for analyses covering more than one wave of CSES and over time. Moreover, the universal coding of variables ensures validity and reliability of empirical research using CSES data. Hence, this dataset enables straight-forward access and research possibilities for the wider scientific public.

Providing one of the most important data sources for comparative electoral research, CSES can be regarded as a constantly growing project of the comparative social sciences. Since its foundation, the number of participating countries increased continuously from 25 to over 50. The WZB has been involved in the CSES program from the beginning, first as host of its founding conference in 1994 and ever since organizing meetings of the CSES Planning Committee and Plenary Sessions.

With this data publication, the WZB and especially its research unit ‘Democracy and Democratization’ lead by Wolfgang Merkel follows its self-conception and tradition of common good production in the realm of empirical research with the goal of enabling and fostering high quality research not just in-house but all over the world.

The CSES 1-3 Harmonized Trend File and an extensive documentation are available for download from the CSES website under the "Data Center" link.